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TI30XAUS.DOC MURFE pruning Pat Hatcher Revised:
06/17/99 4:31 PM Printed: 06/17/99 4:32 PM Page 12 of 21
Probability
A combination is an arrangement of objects in which
order is not important, as in a hand of cards.
"
i
calculates the number of possible combinations of
n
items taken
r

at a time.

Calculate the number of 5-card poker hands that can be

dealt from a deck of 52 cards.

52
"
i
5
J
2598960.
A permutation is an arrangement of objects in which
the order is important, as in a race.
"
j
calculates
the number of possible permutations of
n
items taken
r
at a time.

Calculate the number of possible permutations for the

1st-, 2nd-, and 3rd-place finishers

(

no ties

)

in an 8-

horse race.

8
"
j
3
J
336.
A factorial is the product of the positive integers from 1
to
n
. (
n
must be a positive whole number
69).

Using the digits 1, 3, 7, and 9 only one time each, how

many 4-digit numbers can you form?

4
"
v
24.